Electropneumatic telegraph control relay



May 6 1924.

H. PRATT ELECTROPNEUMATIC TELEGRAPH CONTROL RELAY Filed May '7, 1919 Patented May 6, 1924.

UNITED STATES v f?" i 1,492,7tt

PATENT OFFICE.

HARADEN PRATT, OF SAN FRANCISCO, CALIFORNIA.

ELECTROPNEUMATIC TELEGRAIlPH CONTROL RELAY. 7

Application filed May 7, 1919. Serial No.t295,458.

Tocll whom it may concern:

Be it known that I, HARADEN Penna citizen of the United States, and a resident of the city and county of San Francisco and State of California, have invented an Improvement in Electropneumatic 'Telegraph Control Relays, of which the following isa specification.

Iy invention relates broadly to radio 10 telegraphic communication and more specifically to a means for controlling radio telegraphic transmitters and has for its 'priniary object the provision of means for ac complishing such control, whereby rapid manipulation at operating telegraphic speeds in excess of that possible with ordinary manual manipulation maybe-effected.

With the majority of telegraphic control devices heretofore used in the art, a high difficult toattain, particularly with radio transmitting equipments of large size and large power, where high frequency currents of large amplitude are encountered. This invention provides a means whereby these;

difficulties may be overcome.

A further feature of the invention is the employment, if necessary, of one or more air ated by. a local electric current, the electro-- magnet being designed so that the moving armature 2 has a small inertia and carries the coil 3.. wound on an insulated bobbin which is actuated by the controlling current.

sible because the. permanent magnet 4 having winding 4- permanently energized by speed' of transmitting operation has been the electro-pneumatic telegraph control re small. 7 This small number'of turns is pos-- batterye is very strong, and therefore the requlred mechanical force can lbe'obt-ained' by the use of a small current in the armaturewinding 3. A further reduction in the time constant may be obtained by the Well known method of inserting a resistancein series with the control circuit, and employ-* ing'a correspondingly higher voltage.

This electro-inagnet, therefore, by its construction is capable of faithfully following the rapid current impulses impressed on its armature in high speed telegraphic operatio-n'by any suitable circuit' 3 This invention, however, is not limited to the'particu lar magnet system or circuit arrangement shown, but applies to any electro-inagnet system capable of'being operated from a telegraph control circuit, which" embodies a low mechanical inertia of moving parts and a low electrical timeconstant, in combination with a valve controlled "pneuinat ically operated contact system, substantially as explained hereinafter, c e

The purpose of the pneumatic device is to furnish the necessary mechanical force to operate a relatively hea'vy' metal contact piece, which could not be obtainedfrom the comparatively weak" electro-{nagnetf A valve 5, is directly attached to armature 2, of the electro-inagnet 4 and is moved by l the armature which thus controls asupply of air from pipe 6 at any pressure desired for actuating a double piston structure 7 When current is circulated in the proper direction through coil 3 the valve is moved to the right admitting air under-pressure i through ports 9 to the leftof the double piston structure 7, whichis thereby also moved i to the right. Areversal of the current in coil 3 will move the valve 5 to the left closing ports 9, which cuts offi the air to the cylindrical vspace l6 and openingjports 8, which releases the air confined in the cylinder 1095 to the'atmosphere through openings 11.

The piston valve 5 of this device is from its structure balanced as regards air pres-- sures, and therefore readily follows the movements of the electro-magnet 2, to which it is attached, admitting'or releasingair under pressure to or from the main cylin der of the device. Compressed air is also supplied continuously to the space between the double pistons of the structure 7 through opening 12 from pipe 6, and the two pistons being of the same area are therefore balanced with respect to the pressure in the intervening space as described in the case of the valve 5. lVhen this piston 7 is in its extreme right hand position, air .is admitted through the port 14 producing a back ressure upon the structure in space 15. is back pressure is less than the forward pressure produced in space 16, because of the small aread piston 17, and the piston structure 7 therefore does not move. When, however, air pressure in space 16 is removed, the pressure in space 15 is immediately available and acts to return piston strucv ture 7 to its left hand position, and the air escapes through ports 18 ,whichare uncovered.

Piston structure 7 directly operates a contact 19 which makes and breaks the current in the circuit 20, which is being controlled. A port 21 opened or closed by the movement of piston 7 furnishes compressed air to the electrical contacts 19 and 22 through tube 23, insulated from cylinder 10 by means of bushing 24, so that when the contacts are opened a blast of air will ensue, thereby blowing out any arc which may develop when the circuit is broken at that point and which also assists in coolingthe contacts. The stationary contact 22 is insulated-from the base 1 by an insulating section 25.

Having described my invention,-what I claim and wish to protect byLetters Patent of the United States is:

1. An electro-pneumatic key including a permanent magnetic field, an armature having a winding associated therewith, a circuit including means to supply electric impulses of a telegraphic nature to said winding, a pneumatic valve supporting said armature in said field and operating in response to said armature, a pneumatically operated piston structure in alignment with and controlled by said valve, and an electrical contactor directly attached to said piston structure. v

2. A circuit controller including a con trolling valve, means for operating. said valve, a multiple piston structure, a source of fluid pressure, means controlled by saidvalve for placing said piston structure under unidirectional pressure and create a movement thereof, means controlled by the movement of said structure to create a pressure thereon less than and opposed to said first pressure, means controlled by said valve to release said first pressure and permit the piston structure to return to normal position, means controlled by the return movement of said piston structure to release said second pressure, and circuit controlling means operated by said piston structure.

3. A circuit controller including a conaread piston under pressure and releasing said space from pressure, and circuit controlling means operated by said piston structure.

4:. Means for converting feeble"periodical' I effort into intensified periodical eifort of the same frequency'comprisinga fluid pressure actuated motor havinr, a controllingvalve.

actuated by said feeble eifort,a multiple piston structure cylindrically'enclosed, a source of fluid pressure, a series of intake and ex haust ports, all being so coordinated that the valve opens one of said ports to permit said pressure to create a unidirectional mo- I tion of said piston structure, the structure while in motion opens a second port topermit said pressure to create'a pressure unequally opposing said motion, the valve opensa third port to release said first pressure and permit a return motion of said piston structure, and the piston structure opens a fourth port to release said second pres sure, and means attached to said piston structure for utilizing the resulting inte'nsi fied effort of said piston structure.

5. Means for converting feeble-periodical eifort into intensified periodical effort of A i the samefrequency comprising a'fluid prjes sure actuated motor having a controlling valve actuated by said feeble 'eifort, a multiple piston structure, a source offluidpressure, means controlled ;by 7 said valve for 1 placing said'piston structure under unidi rect onal pressure and create a movement of said structure to create a pressure there-- on less than'and opposed to said first pressure, means controlled by said valve to release said first pressure and permit the piston structure to return'to normal position,

means controlled by the return movement of said'piston structure to release said second pressure, and means attached to said piston structure for utilizing the resulting intensi fied effort of said structure.

6. Means for converting feeble periodical effort into intensified periodical effort of the same frequency comprising a fluid pressure actuated motor'having a controlling valve actuated by said feeble effort, a triple piston structure cylindrically enclosed, two of said pistons being equal aread and adjacent and one of lesser area, a source of fluid pressure,

thereof, means controlled by the movement 1 means for maintaining the space between the lesser aread piston under pressure and said equal aread pistons under constant releasing said space from pressure, and

pressure, means controlled by said valve for means attached to said piston structure for 10 putting one of said equal aread pistons unutilizing the resulting intensified efiort of der pressure and releasing it from pressure, said structure.

means controlled by the second equal aread piston for putting the space between it and HARADEN PRATT.- 

